Despite its importance, the proposed extension of the Orange Freeway down the Santa Ana River Channel to hook up with the San Diego Freeway is so expensive as to make the project little more than a dream at this time, county transportation officials were told Monday.

A final study of building the 10.5-mile, six-lane extension of the Orange Freeway (California 57) produced the same price tag as the preliminary study: $810 million.

"The effort and energy that it would take to raise this amount of money makes the project somewhat questionable at this time," Stan Oftelie, executive director of the Orange County Transportation Commission, told commission members Monday.

"But it doesn't take it completely off the table, particularly when you take a good look at the overall benefits to our transportation system that will be derived from finishing this missing link."

Wanted Deeper Study

Oftelie said the commission struck out in its efforts to get the Southern California Assn. of Governments to help finance a more detailed $240,000 study of the proposed extension, which would run from the freeway's present terminus in Orange south along the river channel to the San Diego Freeway in Costa Mesa.

Commission members raised the possibility of reapplying for SCAG study funds next year, and directed the staff to see if other government agencies involved in flood control along the river would help pick up part of the tab.

Both studies were done by Deloitte Haskins & Sells.

The initial study looked at three proposals for extending the freeway. Two proposals had the northbound and southbound lanes, either at ground level or slightly elevated, separated by the river. The third proposal involved building the entire extension on the east side of the river at a height of 40 feet.

The report found that the extension is "technically feasible," Oftelie said, but "it is extremely expensive." The study found there would be some savings--although the extent was not known--by combining the extension with the proposed $1.1-billion federal flood protection plan for the river. Staff members of the Army Corps of Engineers, which is designing the flood control plan that is now before a House-Senate conference committee, have said that the two projects could be compatible, according to the earlier study.

Transportation Commission Chairman James Roosevelt said that for the long range the building of a major north-south freeway was probably the most significant project likely to come before the commission.